Session B19: Accelerator Technology

Live

The proposed US Electron-Ion collider will be very challenging in areas of LLRF, RF and beam longitudinal dynamics. Because of the dissimilarity of the electron and ion rings, the RF transients created by the clearing gaps in the current distributions will be very different in the two rings. These transients shift the synchronous phase of the beams as a function of RF bucket position, can impact the luminosity through shifts in longitudinal position of the IP, will require management of the required RF power, and will affect the performance of the RF and LLRF control loops. A machine design that uses superconducting crab cavities will also have sensitivity to gap transient and synchronous phase variations along the filled buckets in a turn with variations in crab cavity voltage seen by each bunch. This makes the problem of managing the effects of the gap transients crucial to the operation of the EIC. This talk presents methods to study the dynamics of the RF and LLRF systems for a strawman EIC machine design example. Methods are shown to estimate the RF gap transients as well as possible remedies to match the gap transients in the two dissimilar EIC rings. This work estimates the RF power required, gap transients and longitudinal coupled-bunch instabilities due to the baseline cavity fundamental impedance. The talk motivates the importance of tools and methods to estimate these effects as part of the early design phase of the Electron-Ion collider projects.   

Live

Radiofrequency cavities operated in the TM010 mode are the building blocks of most normal-conducting linear accelerators. A dielectric loaded TM020 cavity is proposed which would require approximately half the RF power as a TM010-mode cavity to generate the same accelerating fields, while keeping other accelerator properties the same. Since RF power represents both large capital and operating expenses for accelerator facilities, such an efficiency improvement represents a significant benefit. It is also of potential use for small accelerators where both power availability and waste heat dissipation are concerns, such as small industrial or space-based applications. The analytical work and computational simulation done on CST microwave studio of this type of RF structure are presented.   

Live

The LINAC at the Los Alamos Neutron Science Center (LANSCE) has been testing a phase scan method as a boost to its original the Delta-T method. The Delta-T process optimizes the phase and amplitude set points of each module based on the time-of-flight measurements at two subsequent detectors. The new phase scan method, with the help of an upgrade to a faster readout system, scans over the whole phase range with less time than the original optimization procedure while provides a wealth of information. In this study, I will discuss the amplitudes of the RF modules extracted from the phase scan data, and compare them with the Klystron current measurements and the designed values.